This article is in need of attention from a psychologist/academic expert on the subject.Please help recruit one, or improve this page yourself if you are qualified.This banner appears on articles that are weak and whose contents should be approached with academic caution

.

Pierre-Cécile Puvis de Chavannes: The Dream, 1883

A girl sleeps in her bed, before reaching REM sleep.

A dream is the experience of imagined images, voices, or other
sensations during sleep. Dreams often portray events which are
impossible or unlikely in reality, and are usually outside the control
of the dreamer. Many people report experiencing strong
emotions while dreaming, and frightening or upsetting dreams are referred to as nightmares. The scientific discipline of dream research is
oneirology.

Dreams have a long history both as a subject of conjecture and as a
source of inspiration (artistic or otherwise). Throughout history, people have sought meaning in dreams. They
have been described physiologically as a response to
neural processes during sleep, psychologically as
reflections of the unconscious, and spiritually
as messages from God or predictions of the future
(oneiromancy).

Most scientists believe that almost all humans dream with approximately the same frequency. Even those who rarely recall dreams report having them if awakened during rapid eye movement REM sleep. Dreaming in animals varies from species to species.

Contents

Understanding dreams

The expectation fulfilment theory of dreams

Psychologist Joe Griffin, one of the founders of human givens psychology, has put forward an explanation for why humans dream: The expectation fulfilment theory of dreaming. He reviewed all the available scientific evidence and conducted a 12 year program of research that showed that all dreams are expressed in the form of sensory metaphors.[1][2] Interviewed by New Scientist he explained how his findings "show that ordinarily dream sleep does a great housekeeping job for us. Each night it brings down our autonomic arousal level. Dreams are metaphorical translations of those waking introspections – emotionally arousing feelings and thoughts – that we don’t act upon while we are awake. Once aroused, our brain has to complete that cycle of arousal and, if we don’t complete it in the external world, we do so in our dream sleep. The patterns of arousal are metaphorically acted out and thereby deactivated." (New Scientist. April 12th pp44-47)

Research by Michel Jouvet indicated that instinctive behaviours are programmed during the REM state in the foetus and the neonate. This is necessarily in the form of incomplete templates for which the animal later identifies analogous sensory components in the real world. These analogical templates give animals the ability to respond to the environment in a flexible way and generate the ability to learn, rather than just react.[3]

Griffin pointed out that one can see this process when, for example, a baby seeks out and sucks on anything similar – analogous to – a nipple, like a finger or rubber teat. Once an instinct-driven pattern is activated and becomes an expectation, it can normally only be deactivated by the actual carrying out of the programmed behaviour by the central nervous system, and this clearly does not give animals the flexibility needed to survive.

"Letting off steam" usually dissipates anger, but if animals were to act out their emotions instantly every time they were emotionally aroused, that would be disastrous. So animals needed to evolve the ability to inhibit arousals when necessary and deactivate them later when they could do no harm. Griffin hypothesized that that is why animals evolved to dream. During REM sleep, unfulfilled emotional expectations left over from the day are run out in the form of metaphors, thus deactivating them and freeing up the brain to deal with the new emotionally arousing events of the following day. Without dreams fulfilling animals' expectations by acting them out metaphorically, and thereby quelling the autonomic nervous system, animals would need a vastly bigger brain.

Griffin's expectation fulfilment theory of dreams states that:

Dreams are metaphorical translations of waking expectations.

Expectations which cause emotional arousal that is not acted upon during the day to quell the arousal, become dreams during sleep.

Dreaming deactivates that emotional arousal by completing the expectation pattern metaphorically, freeing the brain to respond afresh to each new day.

Neurology of dreams

There is no universally agreed-upon biological definition of dreaming. Dreams are typically associated with REM sleep, a phase of brain activity which occurs towards the end of the sleep cycle. REM sleep is characterized by rapid horizontal eye movements, stimulation of the pons, increased respiratory and heart rate, and temporary paralysis of the body. Subjects awakened during REM sleep usually report having been dreaming. However, a small fraction of subjects also report dreaming in other phases of sleep. Some neurologists even group mental phenomena such as daydreaming under the umbrella of dreaming.

Some studies on time sense during dreams have determined that a subject's time sense during a dream closely matches their time sense during waking activity. In other words, if a dream feels like it lasted twenty minutes, these studies suggest it was indeed about twenty minutes. However, other studies have found this to be inaccurate. Thus, there is some debate regarding the distribution of time in a dream corresponding to reality.

It is unknown where in the brain dreams originate — if there is such a single location — or why dreams occur at all. However, there are many competing theories of the neurology of dreams.

The activation synthesis theory developed by Allan Hobson and Robert McCarley asserts that the sensory experiences are fabricated by the cortex as a means of interpreting random signals from the pons. They propose that in REM sleep, the ascending cholinergic PGO (ponto-geniculo-occipital) waves stimulate higher midbrain and forebrain cortical structures, producing rapid eye movements. The activated forebrain then synthesizes the dream out of this internally generated information. They assume that the same structures that induce REM sleep also generate sensory information. [5] Memory, attention and the other features lacking in the dream state are taken to depend on the neurotransmitters norepinephrine and serotonin, which are present in reduced concentrations during REM sleep. This chemical change is hypothesized to produce a psychotic state, as well as a lack of orientation.

On the other hand, research by Mark Solms suggests that dreams are generated in the forebrain, and that REM sleep and dreaming are not directly related. [6]

Combining Hobson's activation synthesis hypothesis with Solms's findings, the continual-activation theory of dreaming presented by Jie Zhang proposes that dreaming is a result of brain activation and synthesis, and at the same time, dreaming and REM sleep are controlled by different brain mechanisms. The theory is developed through a series of hypotheses. By introducing a temporary memory stage into the memory process, Zhang first proposed that the memory formed during waking time is not saved directly into the long-term memory; instead it is saved into a temporary memory store. He, then, divides brain into two subsidiary systems: the conscious brain and the non-conscious brain. Zhang hypothesizes that the function of sleep is to process, encode and transfer the data from the temporary memory to the long-term memory. NREM sleep processes the conscious related memory (declarative memory); and REM sleep processes the non-conscious related memory (procedural memory). He further hypothesizes that both conscious and non-conscious subsidiary systems of brain have to be continually activated through their life times. When the level of activation of either subsidiary system descends to a given threshold, a continual-activation mechanism will be triggered to maintain brain continual activation. Zhang assumes that during REM sleep, the non-conscious part of brain is busy to process the procedural memory; in the meanwhile, the level of activation in the conscious part of brain will descend to a very low level as the inputs from the sensory are basically disconnected. This will trigger the continual-activation mechanism to generate a data stream from the memory stores to flow through the conscious part of brain. Zhang suggests that this pulse-like brain activation is the inducer of each dream. He proposes that, with the involvement of brain associative thinking system, dreaming is, thereafter, self maintained with dreamer's own thinking until the next pulse of memory insertion. This explains why dreams have both characteristics of continuity (within a dream) and sudden scene changes (between two dreams). [7][8]

Eugen Tarnow suggests that dreams are ever present excitations of the long term memory system, even during waking life — McCarley also observes that when asked to recall their last thought, subjects often reported somewhat hallucinatory thoughts. The strangeness of dreams is then due to long-term memories being stored in "dream format"; this is reminiscent of the Penfield & Rasmussen’s findings that electrical excitations of the cortex give rise to experiences similar to dreams. During waking life an executive function interprets long term memory consistent with reality checking.

The English psychologist Stan Gooch suggests that dreams are a product of the Cerebellum, a part of the brain located at the rear of the cortex. The Cerebellum is a region of the brain that plays an important role in the integration of sensory perception and motor output. It also has its own set of optic fibres, which Gooch proposes as a reason for REM during sleep, in short, that a part of the brain connected to the eyes is still experiencing the dream as an image.

Using dreams in therapy

The expectation fulfillment theory of dreams has introduced a more practical way of using dream metaphors in therapy. Human givens therapists know that dream metaphors that clients bring to therapy have therapeutic value because they can often grasp through the metaphor what is worrying their patient. They can then help clients to see more objectively what is troubling them. Depressed people dream more intensely than non-depressed people, and the expectation fulfillment theory explains why Griffin also proposed that hypnosis is most usefully defined as a direct route to activating the REM state, and that all hypnotic phenomena can be explained with this insight. Since trance and suggestion play such an important role in psychotherapy, this fact is of great significance to psychotherapists and counsellors.

Embodied Imagination is a therapeutic and creative form of working with dreams and memories pioneered by Robert Bosnak and based on principles first developed by Carl Jung, especially in his work on alchemy, and on the work of James Hillman, who focused on soul as a simultaneous multiplicity of autonomous states. From the point of view of the dreaming state of mind, dreams are real events in real environments. Based on this notion, one can “re-enter” the landscape of a dream and flashback to the images, whether it is a memory from waking life or from dreaming. One enters a hypnagogic state—a state of consciousness between waking and sleeping--and then, through the process of questioning, images are explored through the perspective of feelings and sensations manifested in the body, enabling new awareness to develop.

Psychodynamic interpretation of dreams

Both Sigmund Freud and Carl Jung identifys dream as an interaction between the unconscious and the conscious. They also assert together that unconscious is the dominant force of the dream, and in dreams it conveys its own mental activity to the perceptive faculty. While Freud felt that there was an active censorship against the unconscious even during sleep, Jung argued that the dream's bizarre quality is an efficient language, comparable to poetry and uniquely capable of revealing the underlying meaning.

Dreams of Absent Minded Transgression

Dreams of Absent Minded Transgression (DAMT) (sometimes pronounced damnit) dreams are dreams where the individual dreaming absentmindedly performs an action that they have been trying to stop (a classic example being a smoker trying to quit dreams of lighting a cigarette). Subjects that have had DAMT dreams have reported awaking with intense feelings of guilt. Some studies have shown that DAMT dreams are positively correlated with successfully stopping the behavior compared to control subjects who did not experience these dreams. [9]

Supernatural interpretations of dreams

The mysterious and often bizarre nature of dreams has led many to interpret dreams as divine gifts or messages, as predictions of the future, or as messages from the past. Alternatively, the idea of the "dream world" as real and the "day world" as imagined is another supernatural interpretation of dreams. Profound dreams believed to be sent by God have led to conversion to another religion.

Western philosophers of a skeptical bent (notably René Descartes) have pointed out that dream experiences are indistinguishable from "real" events from the viewpoint of the dreamer, and so no objective basis exists for determining whether one is dreaming or awake at any given instant. One must, they argue, accept the reality of the waking world on the basis of faith.

Dreaming in animals

For a long time true dreaming had only been positively confirmed in humans, but recently there have been research reports supporting a view that dreaming occurs in other animals as well. Animals certainly undergo REM sleep, but their subjective experience is difficult to determine. The animal with the longest average periods of REM sleep is the armadillo. It would appear that mammals and birds are the only, or at least most frequent, dreamers in nature, which is perhaps related to their sleep patterns. Many animals such as frogs probably do not sleep at all (except when hibernating, which is a different kind of state).

Some researchers have managed to block the brain mechanism that paralyzes the body during dreaming [citation needed]. With this method it has been discovered that a cat seems to dream mostly about chasing prey and playing with it. On a more basic level, many dog owners have also noted that their pets sometimes move their legs as if running or even make weak barking noises while asleep, or that their pets suddenly wake up and appear to think that a character from a nightmare is actually real.